Nature: Bacterial infection destroys the sense of smell

When someone has food poisoning, it may take a while before they want to eat something that makes them sick again, and the same goes for fruit flies

Ilona Grunwald Kadow, a neuroscientist at the Technical University of Munich (who was not involved in the study), said that the authors "revealed a mechanism that links gut bacteria to behavior at the genetic, neuronal, and organismal level

Previous studies have shown that aging fruit flies experience a dramatic increase in inflammation

Heinrich Jasper and his colleagues began to reproduce the results of the published research, confirming that the sense of smell of fruit flies decreases with age

The researchers let fruit flies choose between ordinary foods and foods containing non-lethal intestinal pathogens

"We quickly realized that this decline or change in olfactory perception must also be an adaptation process of young animals.

Once the research team figured out which cytokines were released from the infected intestine, they could guess which pathways might be affected

In this case, the glial cells in the olfactory bulb, instead of neurons, activate STAT, leading to changes in the expression of genes involved in lactic acid metabolism.

Parallel pathways to aging

The research team also found that age-related intestinal inflammation also triggers the same JAK-STAT pathway, from the intestine to glial cells, causing permanent changes in the sense of smell of aging flies

"In young animals, this is a protective mechanism.

Grunwald Kadow said that one of the unresolved issues is how this pathway is conserved in other animals and how inflammation is linked to neurodegeneration-this is also one of Jasper’s first questions: “If in fruit flies , Having [some kind of] microbiota does trigger a mechanism similar to aging, so this may also explain why some people develop neurodegenerative diseases earlier than others?"

(Biocom)